1. Field of the Invention
The present invention relates to end closures for containers having a push open lid portion for providing access to material within the container. The end closure includes a base portion fixed to the container having an initially closed lid or flap portion and a flat bottomed rotatable closure portion for selectively closing off the opening defined by the push open lid portion. The rotating portion is retained on the base by its marginal edges so that the base remains intact until opened. More particularly, the present invention relates to an end closure having a push open lid portion and which includes one or more elements for cooperating with corresponding gripping elements to hold the lid portion in its open position.
2. Description of the Related Art
Many food and drink products such as grated cheese, herbs and seasonings, and powdered drinks are provided in containers with plastic closures having a rotatable portion with a permanent opening through a portion thereof which selectively provides access to an opening through a lower portion of the container closure. The opening through the lower portion is typically defined by an openable lid portion which is pushed towards the container interior so as to break a seal defined between the openable lid portion and the remainder the closure. After the frangible seal is broken, the openable lid portion flexes or bends about a "living hinge" which permanently connects the lid portion to the remainder of the closure. In this manner, the end closure can be used to seal the contents of the container prior to use and, when it is desired to access the container contents, the rotatable portion of the lid can be rotated so that the opening therethrough is aligned with the openable lid portion. Pressure is then applied to the openable lid portion to punch open the same and cause the openable portion to bend about the living hinge. When it is desired to temporarily close off the thus opened lid, the rotatable portion of the lid is rotated to cover the opening defined by the openable lid portion.
Such containers are advantageous as they allow selective access to the container contents while providing a closure for the contents between uses. However, a disadvantage with such end closures is that the lid portion which has been pushed open, due to the resilience of the living hinge, tends to flex back towards its closed portion thereby restricting the size of the pour opening. This particularly occurs when the container is inverted to pour powdered material or the like from therewithin. Occasionally, the lid portion can almost completely block the opening in the closure. It would therefore be desirable to provide a structure which retains the openable lid portion in its open position so that it will not interfere with access to the container contents.
FIGS. 1-7 show various prior attempts to develop end closures that exhibit a type of flat rotor that was rotatably retained on a base without use of a rivet type connector or a mechanism to hold a press-open lid in an open position.
FIGS. 1 and 2 correspond to a type of end closure suitable for placement at the end of a container to close the interior. The end closure is comprised of a base and a rotor retained on the base and in a central portion of the base which extends radially outwardly from the rotor. The periphery of the rotor is provided with a raised or upwardly extending edge that includes a substantially C-shaped cross-section annular ring that corresponds to a reverse C-shaped cross-sectional retaining groove formed within the base. The bottom surface of the rotor was essentially a flat planar surface and included a cut-out opening and shaker openings. The base include a smile-shaped knockout panel which would be opened by removing the entire piece of plastic. The base was also characterized by two levels, one corresponding to the surface, that extended radially outwardly from the rotor, the other located beneath the rotor.
The end closure shown in FIGS. 3-5 is another version where the rotor, so marked, also had a flat planar bottom surface. The rotor was held in the base, as marked, by means of an annular extension projecting slightly beyond the peripheral edge of the rotor and a mating groove formed in the base. Both the annular extension and groove were radiused. The bottom surface of the rotor was spaced above the upper surface of the base against which it was positioned forming an open space therebetween in which debris or material from the container could collect. Also, the radiused extension/groove approach for retaining the rotor on the base was not sufficiently positive to hold the rotor in place and provide a suitable seal for the contents inside the container.
The end closure shown in FIGS. 6-7 shows a closure that holds the openable lid open. The bottom plan view of the base in FIG. 6 and the cross-sectional view in FIG. 7 shows the use of two tapered conical projections that extended downwardly from the bottom surface of the base toward the interior of the container on which the end closure would be used. The push open lid or flap is characterized by a straight hinge along its rear edge. Two straight sides diverge at oblique angles away from opposing ends of the hinge toward the front of the lid terminating at an arched front edge which joins the outer ends of those straight sides. The straight sides provide a special shape that will pass beyond the tapered projections to the position shown in FIG. 7 with minimum interference yet provide sufficient contact so that the projections hold the flap open. Depending upon the stiffness of the plastic of the hinge and the lid, the lid would need to be bent beyond 90.degree. to move the lid beyond the projections in order to arrive at the position shown for the flap in FIG. 7. FIGS. 6a and 6b show top and bottom plan views of the rotor used on this end closure. The rotor was characterized by planar top and bottom surfaces, by a square cornered peripheral edge that mated with a radiused groove, as shown in FIG. 7, which was similar to the groove shown in FIG. 5 for retaining the rotor.